Crash on RHI with Opacity Mask effect

When applying Opacity Mask effect on QML project running on Vulkan backend there is expected a crash. Detailed crashlog is missing but steps to reproduce are

• include qt5compat module in the project
• use Qt Graphical Effects
• apply Opacity Mask effect
• Happens both on Vulkan and OpenGL backends with RHI

Actual result (OpenGL): Crash and this is written to debug log:

qt.rhi.general: Created OpenGL context QSurfaceFormat(version 3.2, options QFlags<QSurfaceFormat::FormatOption>(), depthBufferSize 24, redBufferSize 8, greenBufferSize 8, blueBufferSize 8, alphaBufferSize 0, stencilBufferSize 8, samples 0, swapBehavior QSurfaceFormat::DefaultSwapBehavior, swapInterval 1, colorSpace QColorSpace(), profile  QSurfaceFormat::NoProfile)qt.rhi.general: OpenGL VENDOR: Qualcomm RENDERER: Adreno (TM) 612 VERSION: OpenGL ES 3.2 

Shader for Opacity Mask is taken from the qbs file provided by qt5compat module.